1.创建表单 index.jsp
<html> <head> <title>注册</title> </head> <body> <form method="post" action="register.jsp"> 用户名：<input type="text" name="username"><br> 密码：<input type="text" name="password"><br> 性别：<input type="text" name="gender"><br> 年龄：<input type="text" name="age"><br> <button type="submit">注册</button> </form> </body> </html>2.创建JAVABean User.java
package bean; public class User { private String username; private String password; private int gender; private int age; private int status; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int getGender() { return gender; } public void setGender(int gender) { this.gender = gender; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public int getStatus() { return status; } public void setStatus(int status) { this.status = status; } }3.创建跳转表单 register.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <jsp:useBean id="user" class="bean.User"></jsp:useBean> <jsp:setProperty name="user" property="*"></jsp:setProperty> <% Class.forName("com.mysql.jdbc.Driver"); String url="jdbc:mysql://127.0.0.1:3306/book?user=root&password=root"; Connection connection= DriverManager.getConnection(url); String sql="insert into user(username,password,gender,age) values('"+user.getUsername()+"','"+user.getPassword()+"',1,23)"; Statement stmt = connection.createStatement(); int count = stmt.executeUpdate(sql); if(count == 0){ out.print("注册失败"); }else{ out.print("注册成功"); } %> <jsp:getProperty name="user" property="username"/>实现数据库的增删改查的操作 1.使用Statement增加数据
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <jsp:useBean id="user" class="bean.User"></jsp:useBean> <jsp:setProperty name="user" property="*"></jsp:setProperty> <% Class.forName("com.mysql.jdbc.Driver"); String url="jdbc:mysql://127.0.0.1:3306/book?user=root&password=root"; Connection connection= DriverManager.getConnection(url); String sql="insert into user(username,password,gender,age) values('"+user.getUsername()+"','"+user.getPassword()+"',1,23)"; Statement stmt = connection.createStatement(); int count = stmt.executeUpdate(sql); if(count == 0){ out.print("注册失败"); }else{ out.print("注册成功"); } %> <jsp:getProperty name="user" property="username"/>使用PreparedStatement增加数据
<% Class.forName("com.mysql.jdbc.Driver"); String url ="jdbc:mysql://127.0.0.1:3306/book"; Connection connection = DriverManager.getConnection(url,"book","book"); String sql = "insert into user(username,password,gender,age) values (?,?,?,?)"; PreparedStatement Ws = connection.prepareStatement(sql); Ws.setString(1,request.getParameter("username")); Ws.setString(2,request.getParameter("password")); Ws.setInt(3,request.getParameter("gender")); Ws.setInt(4,request.getParameter("age")); ResultSet rs = Ws.executeQuery(); %>数据库原始数据 运行代码 输入如下数据
插入数据成功 运行结果 数据库数据如下 2.使用Statement删除数据
<% Class.forName("com.mysql.jdbc.Driver"); String url="jdbc:mysql://10.3.22.15:3306/book?user=root&password=root"; Connection connection =DriverManager.getConnection(url); Statement stmt =connection.createStatement(); String sql = "delete from user where id = 5"; int count = stmt.executeUpdate(sql); if(count == 0){ out.print("删除失败"); }else{ out.print("删除成功"); } %>使用PreparedStatement删除数据
<% Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost:3306/book"; Connection connection = DriverManager.getConnection(url,"root","root"); String sql = "delete from user where id = ? "; PreparedStatement pstm = connection.prepareStatement(sql); pstm.setInt(1,5); %>运行前数据库数据如下 删除ID为5的数据 运行结果如下，ID为5的数据被删除 3.使用Statement修改数据
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <jsp:useBean id="user" class="bean.User"></jsp:useBean> <jsp:setProperty name="user" property="*"></jsp:setProperty> <% Class.forName("com.mysql.jdbc.Driver"); String url="jdbc:mysql://127.0.0.1:3306/book?user=root&password=root"; Connection connection =DriverManager.getConnection(url); Statement stmt =connection.createStatement(); String sql ="update user set age = 25 where id = 3"; int count = stmt.executeUpdate(sql); if(count == 0){ out.print("修改失败"); }else{ out.print("修改成功"); } %>使用PreparedStatement修改数据
<% Class.forName("com.mysql.jdbc.Driver"); String url ="jdbc:mysql://127.0.0.1:3306/book"; Connection connection = DriverManager.getConnection(url,"book","book"); String sql="update user set age=? where age=?"; PreparedStatement pstm=connection.prepareStatement(sql); pstm.setInt(25,3); %>修改数据前，数据库数据如下 要修改ID为3的用户年龄为25，运行成功 ID为3的用户年龄变为25 4.使用Statement查询数据
<% Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost:3306/book"; Connection connection = DriverManager.getConnection(url,"root","root"); Statement stmt = connection.createStatement(); String sql = "select * from user where username = '"+request.getParameter("username")+"'"; ResultSet rs = stmt.executeQuery(sql);*/ while (rs.next()) { out.print(rs.getString("username")+"-"+rs.getString(3)+"<br>"); } %>使用PreparedStatement查询数据
<% Class.forName("com.mysql.jdbc.Driver"); String url = "jdbc:mysql://localhost:3306/book"; Connection connection = DriverManager.getConnection(url,"root","root"); String sql = "select * from user where username = ?"; PreparedStatement Ws = connection.prepareStatement(sql); Ws.setString(1,request.getParameter("username")); ResultSet rs = Ws.executeQuery(); while (rs.next()){ out.print(rs.getString("username")+"-"+rs.getString(3)+"<br>"); } %>数据库数据如下 查询admin 查询成功 结果如下：
